Specimen tilting device for an electron optical device

ABSTRACT

A specimen tilting device for inserting a specimen into the objective lens of an electron optical device in a direction perpendicular to the electron optical axis of the microscope. The specimen stage is located on a plane defined by two tilting axes perpendicular to said electron optical axis. The stage may be rotated about each tilting axis so as to tilt or incline said specimen in any direction and at any desired angle.

United States Patent 1191 Mikajiri Dec. 11, 1973 [54] SPECIMEN TILTING DEVICE FOR AN 2,418,903 4/1947 Runge 250/495 ELECTRON OPTICAL DEVICE 3,521,056 7/1970 Suzuki 250/495 [75] Inventor: Akio Mikajiri, Tokyo, Japan FOREIGN PATENTS O A LICATIONS Assigneez Nihon Denshi Kabushiki Kaisha 891,589 9/1953 Germany 1. 250/49.5

Tokyo, Japan Primary Exammer-W1ll1am F. Lindquist 1 Flled! J 1972 Att0rney-John M. Webb [21] Appl. No.: 262,208

[57] ABSTRACT 52 U.S. Cl. 250/442, 250/311 A Specimen tilting device inserting a Specimen 51 Int. Cl H0lj 37/26, 00111 23/02 the i lens elem P device in a [58] Field of Search 250/495 B rectio" Perpendicular the 61mm" 1Pticalaxis microscope. The specimen stage is located on a plane [56] References Cited defined by two tilting axes perpendicular to said elec- UNITED STATES PATENTS tron optical axis. The stage may be rotated about each tilting axis so as to tilt or incline said specimen in any filrglgen et a1 250/495 direction and at any desired angle 3:l79,799 4/1965 Valdre 250/495 4 Claims, 8 Drawing Figures PATENIED DEC 1 1 i975 sum in? 3 SPECIMEN TIL'IING DEVICE FOR AN ELECTRON OPTICAL DEVICE This invention generally relates to a specimen tilting device for electron microscopes or the like. More particularly, however, it relates to a specimen tilting device wherein the specimen is placed in the objective lens of the microscope in a direction perpendicular to the electron optical axis. This particular mode of entry is known as side entry and such a device is known as a side entry goniometer." An advantage of a side entry goniometer is that the maximum degree of tilt with respect to the axis coincident with the direction of specimeninsertion is large, for example, up to a 60 tilt being possible. However, without making the device complicated and bulky, the angle of tilt about the axis perpendicular to the direction of specimen insertion is quite limited, thereby, in effect, limiting the function of the side entry goniometer to that of a single tilt goniometer.

It is a purpose of this invention to provide a specimen tilting device capable of overcoming the abovedescribed limitations. It is a further purpose to provide a double tilt goniometer. It is yet another purpose of this invention to provide a double tilt goniometer which is compact, easy and cheap to manufacture and easy to operate. It is yet another purpose to provide a goniometer having as a preferred feature a mechanism for moving the specimen along the optical axis.

Briefly, the device according to this invention comprises a body rotatably attached. to the column of an electron microscope or the like, the longitudinal axis of said rotating body generally perpendicularly intersecting the electron optical axis of said microscope or the like. A frame is fixed to the rotating body having thereon a specimen holder for holding a specimen. At least one wheel is fixed to the specimen holder. Two pivots pivotally mount the specimen holder and wheel or wheels. The axis between said two pivots is perpendicularly disposed with respect to the electron optical axis and the longitudinal axis of the rotating body. Rods for rotating said wheel or wheels are arranged to be operated externally.

This invention will become apparent by reading the following detailed description in conjunction with the accompanying drawings in which: 4

FIG. 1 is a sectional view showing one embodiment of this invention;

FIG. 2 is a sectional view taken along the line A-A in FIG. 1;

FIG. 3 is a sectional view showing a variation on FIG.

FIGS. 4 and 5 are diagonal perspective views showing other variations on FIG. 2;

FIG. 6 is a sectional view showing another embodiment of this invention;

FIG. 7 is a diagonal blown-up perspective view of the circled area B shown in FIG. 6; and,

FIG. 8 is a sectional view taken along the line C-C in FIG. 6.

Referring to FIGS. 1 and 2, 1 represents a section of a microscope column, for example, the objective lens yoke and 2 represents a rotating body rotatably mounted in the column wall by means of a screw member 3. The portion of the rotating body 2 orientated inside the column 1 intersects the electron optical axis of the microscope perpendicularly; that is, the axis denoted by X in FIG. 1 intersects the axis denoted by Z in FIG. 2 perpendicularly. A knob 4 attached to the ex ternal end of the rotating body 2 serves to rotate the rotating body 2 about its X-axis. A frame 5 attached to the other end of the rotating body 2 is arranged between pole pieces 6a and 6b forming part of the objective lens. Grooved wheels 8a and 8b are attached to each side of the specimen holder 7. The grooved wheels are mounted on shafts 9a and 9b which rest and rotate in V-shaped grooves 10a and 10b cut into the upper surface of frame 5. The orientation axis of the shafts 9a and 9b, that is to say, the axis denoted by Y in the figures, lies at right angles or perpendicular to the optical axis Z and the rotating axis X of the rotating body 2.

A specimen 11 is held in the specimen holder 7 by means of a securing member 12 so as to lie on a plane defined by axis X and axis Y. Rods 13a and 13b are of a material having elasticity. One end of the rods are fixed to a moving block 15 which is slidably mounted in the frame 5, the other end of the rods resting in the grooved wheels 8a and 8b. A male screw 16 is fixed to rotatable shaft 17 and threaded into the moving block 15. The external end of the shaft 17 is fitted with a knob 18.

Thus, by turning the knob 4, the specimen is tilted or inclined in a certain direction and at a certain angle with respect to the axis X, the amount of tilt being determined by the degree to which the knob 4 is rotated. Further, by turning the knob 18, the moving block 15 is made to slide either backwards and forwards along the axis X which in turn causes the rod 13a and 13b to turn the grooved wheels 14a and 14b, thereby rotating the specimen holder 7, and the specimen contained therein, about the axis Y in accordance with the degree to which the knob 18 is rotated.

In the embodiment shown in FIG. 3, the two grooved wheels have been eliminated by using a sphericalshaped specimen holder mounted on two pivots 20a and 20b secured to the frame 5. The two rods 13a and 13b, instead of resting in the grooved wheels, lie flushly between the frame 5 and the spherical surface 19, thereby rotating the specimenholder about the axis Y by turning, the knob 18 in the same way as in the embodiment described in FIGS. 1 and 2.

.In the embodiment shown in FIG. 4, a pinion 2lrotated by a rack 22 is used instead of the grooved wheels 8a and 8b. A rod 13 is fixed to one end of the rack 22. Shaft 9b, in this case, is fitted with a sphere or ball 23 which is held in a cone-shaped opening (refer to FIG. 8) cut into the upper surface of the frame 5. Thus, by moving the rod 13 backwards and forwards, the specimen holder 7 is tilted about the axis Y, any lateral movement of the holder being prevented by the sphere or ball 23.

In the embodiment shown in FIG. 5, a worm 24 and worm wheel 25 replace the rack and pinion described in FIG. 4. In this case, the worm 24 is fixed to the rotatable shaft 17 (refer to FIG. 1).

FIGS. 6, 7 and 8 show another embodiment of this invention. Referring to the figures, a cylindrical rotating body or bushing 2 is mounted in the column of the electron microscope or the like such that the cylindrical axis passes through the optical axis. A supporting member 26 is mounted in the cylindrical rotating body 2 by a sphere 27 such that the angle between the axis of the cylindrical rotating body or bushing 2 and the supporting member 26 may be varied. A sliding stage 29 joins the bushing 2 and the supporting member 26. The supporting member 26 and the sliding stage 29 each have a curved surface 28 which are arranged to slide one over the other. The surface on the supporting member is convex and the surface on the sliding stage is convex. The center of the curved surface 28 is the center of the sphere 27. The supporting member and the sliding stage are joined by a key 30 and set in keyway 31. A thumbscrew 32 makes contact with the sliding stage 29 and is kept in contact with the stage by a spring 33. A knob 34 for shifting the supporting member 26 also makes contact with sliding stage 29 and is threaded to said member. Spring 35 serves to push the supporting member 26 in the direction of the optical axis. Rotation of the thumbscrew 32 changes the angle between the longitudinal axis of the supporting member and the axis of the cylindrical body or bushing 2.

A frame extends from the supporting member 26 and surrounds the optical axis. A specimen stage 44 is pivotally mounted in the frame 5 by two hollow shafts 9a, and 9b, having an axis perpendicular to the longitudinal axis'of the supporting member 26. The shaft 9a is provided with a groove wheel 8 which enables tilting of the specimen stage 44 about the axis of the shafts. Shaft 9b is provided with a sphere 23 which sits in a cone-shaped opening 57 provided therefor in the frame to thereby restrict the axial movement of the specimen stage 44.

A shaft 17 complete with knob 18 passes through the supporting member parallel to the axis thereof. A right hand threaded screw 16 and a left hand threaded screw 16b are fixed on the shaft 17 and screwed into moving blocks a and 15b respectively so as to shift the blocks in opposite directions when knob 18 is turned. Fixed respectively to the moving blocks 15a and 15b are two rods 13a and 13b, the free ends of which rest in the groove of the groove wheel 18. Therefore, turning knob 18 tilts the specimen stage 44 about its axis.

A specimen holder 7 is mounted on the specimen stage 44. The specimen holder is pivotally mounted on the specimen stage so that it may pivot on an axis parallel to the axis of the supporting member. It is also arranged to slide axially along this axis. This may be accomplished by a V-shaped groove 51 in the bottom of specimen holder 7. A rod 53 secured to the specimen stage 44 is positioned so that when the specimen holder 7 is laid over the specimen stage with the groove 51 lying over the rod 53, the specimen holder may be moved axially and radially with respect to the axis of the rod 53.

A lever or'bell crank 45 is pivotally mounted on specimen stage 44 by pin 47. One arm of lever 45 makes contact with the sidewall of the specimen holder 7 via a convex portion (not shown). The other arms make contact with the opposite wall of the specimen holder by way of a plate spring 49 fixed to said arm of said lever. The lever 45 is operated by a rod 42 passing through the hollow cylindrical axle or shaft 9a. A longitudinal shaft 36 complete with knob 38 passes through the supporting member 26. The shaft terminates in a cam 40 which acts upon a transverse rod 42 passing through the hollow cylindrical shaft 9a. Thus, by turning knob 38, the specimen holder 7 is moved along the guide rod 53 by means of lever or bell crank 44 which is operated by the cam 40 and transverse rod 42.

A second lever or bell crank 6 is pivotally mounted to the stage 44 by means of pin 48. Fixed to the lever 46 is an arm 55 which supports a leg 54 which leg is a cam follower making contact with the sloping cam face 52 on the specimen holder. The lever 46 is operated by a transverse rod 43 against the suitable bias 56 between the stage 44 and the lever providing the necessary returning tension.

A shaft 37 complete with knob 39 passes through the supporting member 36. Shaft 37 terminates in a cam 41. The cam acts upon a transverse rod 43 passing coaxially and slideably through shaft 9b. The transverse shaft acts upon the bell crank 46. Thus, by turning the knob 39, the specimen holder 7 is moved along the optical axis Z by shaft 37, the cam 41, transverse rod 43, the lever 46 and and the leg 54.

By turning knob 34, the supporting member 26, the

frame 5 and the specimen holder 7 are moved along the X axis so as to make the Y axis intersect the optical axis Z. By turning the thumbscrew 32, the supporting member 26 is tilted, the tilting axis or center of tilt being the axial center of the sphere 27. Accordingly, the specimen holder 7 is moved along the Y axis.

Knobs 4 and 18 enable a holder 7 to be tilted in any direction and at any angle in the same way as in the embodiment described in FIG. 1.

I claim:

1. A specimen positioning device for an electron micro-scope or the like comprising a column (10) enclosing the electron optical axis comprising:

A. bushing means (2) comprising a cylindrical shell rotatably secured in the column (1) such that the longitudinal axis of said bushing intersects the optical axis for providing tilting of a specimen about said longitudianl axis;

B. supporting means (26) positioned within said bushing means (2) and secured thereto such that the longitudinal axis of the supporting means may be moved in an angle relative to the longitudinal axis of the bushing means for providing lateral movement of the specimen on an axis generally perpendicular to the optical axis and the longitudinal axis of the bushing means;

C. a frame (5) extending from said supporting means and enclosing the optical axis;

D. a specimen stage (44) mounted in said frame by two cylindrical hollow shafts (9a and 9b,) the axis of said shafts being generally perpendicular to said optical axis and the longitudinal axis of said bushing means (2);

E. at least one wheel (8) secured tosaid specimen stage (44) about one of said hollow shafts;

F. means comprising a rod (17) passing through said supporting means (26) for rottating said wheel (8) and thereby providing tilting of said specimen about the axis of said hollow shafts (9a and 9b);

G. a specimen holder (7) pivotally and slideably mounted on said specimen stage (44) such that the holder can slide on an axis parallel to the longitudinal axis of the supporting means (26) and can tilt about said axis, said specimen holder having a beveled cam surface (52) facing said specimen stage;

H. a first bell crank (45) mounted on said specimen stage for urging the specimen holder along the sliding axis in cooperation with a suitable bias (50) against the action of the first bell crank;

1. means for activating the firstbell crank comprising a transverse rod (42) passing through said cylindri cal shaft (9a) and abutting said first bell crank (45) and a longitudinal rod (36) passing through said supporting means (26) terminating in a cam (40) abutting said transverse rod (42) whereby turning said longitudinal rod turns said cam moving said transverse rod acting upon the first bell crank to move the specimen along the longitudinal axis;

J. a second bell crank (46) mounted on said specimen stage for urging a cam follower (54) along a beveled cam surface (52) on said specimen holder K. means for activating the second bell crank (46) comprising a transverse rod (43) passing through said other cylindrical shaft (9b) abutting at one end on the second bell crank (46) and a longitudinal rod (37) passing through said supporting means (26) terminating in a cam (41) abutting said transverse rod whereby turning said longitudinal rod turns said cam moving said transverse rod acting on the second bell crank to move the specimen along the optical axis.

2. A specimen positioning device as set forth in claim 1 in which the means for rotating the wheel comprises a rotatable shaft passed through the rotating body, a moving block screwed onto said rotatable shaft, and at least one rod fixed to said moving block extending over said wheel.

3. A specimen positioning device as set forth in claim 2 in which at least one rod is made of a material having elasticity, said rod making contact with the wheel.

4. A specimen tilting device as set forth in claim 1 in which one of the two transverse shafts is provided with a sphere, said sphere being fitted into a cone-shaped opening cut into the upper surface of the frame to prevent axial movement of said shaft.

Patent No. 3, 778, 621

Inventor (X) ro tating- (SEAL) Attest:

EDWARD M .FLETCHER, JR. Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Akio Mikajiri It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

After the line listing the application serial number insertthe following:

Claim 1, Column Signed and sealed this 9th day of April 1971+.

C. MARSHALL DANN Commissioner of Patents F ORM PO-IOSO (10-69) USCOMM-DC 60376-P69 fl u.s. GOVERNMENT PRINTING OFFICE u" o-ass-un, 

1. A specimen positioning device for an electron micro-scope or the like comprising a column (10) enclosing the electron optical axis comprising: A. bushing means (2) comprising a cylindrical shell rotatably secured in the column (1) such that the longitudinal axis of said bushing intersects the optical axis for providing tilting of a specimen about said longitudianl axis; B. supporting means (26) positioned within said bushing means (2) and secured thereto such that the longitudinal axis of the supporting means may be moved in an angle relative to the longitudinal axis of the bushing means for providing lateral movement of the specimen on an axis generally perpendicular to the optical axis and the longitudinal axis of the bushing means; C. a frame (5) extending from said supporting means and enclosing the optical axis; D. a specimen stage (44) mounted in said frame by two cylindrical hollow shafts (9a and 9b,) the axis of said shafts being generally perpendicular to said optical axis and the longitudinal axis of said bushing means (2); E. at least one wheel (8) secured to said specimen stage (44) about one of said hollow shafts; F. means comprising a rod (17) passing through said supporting means (26) for rottating said wheel (8) and thereby providing tilting of said specimen about the axis of said hollow shafts (9a and 9b); G. a specimen holder (7) pivotally and slideably mounted on said specimen stage (44) such that the holder can slide on an axis parallel to the longitudinal axis of the supporting means (26) and can tilt about said axis, said specimen holder having a beveled cam surface (52) facing said specimen stage; H. a first bell crank (45) mounted on said specimen stage for urging the specimen holder along the sliding axis in cooperation with a suitable bias (50) against the action of the first bell crank; I. means for activating the first bell crank comprising a transverse rod (42) passing through said cylindrical shaft (9a) and abutting said first bell crank (45) and a longitudinal rod (36) passing through said supporting means (26) terminating in a cam (40) abutting said transverse rod (42) whereby turning said longitudinal rod turns said cam moving said transverse rod acting upon the first bell crank to move the specimen along the longitudinal axis; J. a second bell crank (46) mounted on said specimen stage for urging a cam follower (54) along a beveled cam surface (52) on said specimen holder (7); and, K. means for activating the second bell crank (46) comprising a transverse rod (43) passing through said other cylindrical shaft (9b) abutting at one end on the second bell crank (46) and a longitudinal rod (37) passing through said supporting means (26) terminating in a cam (41) abutting said transverse rod whereby turning said longitudinal rod turns said cam moving said transverse rod acting on the second bell crank to move the specimen along the optical axis.
 2. A specimen positioning device as set forth in claim 1 in which the means for rotating the wheel comprises a rotatable shaft passed through the rotating body, a moving block screwed onto said rotatable shaft, and at least one rod fixed tO said moving block extending over said wheel.
 3. A specimen positioning device as set forth in claim 2 in which at least one rod is made of a material having elasticity, said rod making contact with the wheel.
 4. A specimen tilting device as set forth in claim 1 in which one of the two transverse shafts is provided with a sphere, said sphere being fitted into a cone-shaped opening cut into the upper surface of the frame to prevent axial movement of said shaft. 